Kinetic studies and thermodynamics of oil extraction and transesterification of Chlorella sp. for biodiesel production

In this work, a mixture of chloroform and methanol (1:1, v/v) was applied to oil extraction from Chlorella sp. at 30, 40, 50 and 60 degrees C for 150 min extraction times. Kinetic studies revealed that the values of n and the rate constants were found to depend strongly on temperature. The activatio...

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Veröffentlicht in:Environmental technology. - 1998. - 35(2014), 5-8 vom: 30. März, Seite 891-7
1. Verfasser: Ahmad, A L (VerfasserIn)
Weitere Verfasser: Yasin, N H Mat, Derek, C J C, Lim, J K
Format: Aufsatz
Sprache:English
Veröffentlicht: 2014
Zugriff auf das übergeordnete Werk:Environmental technology
Schlagworte:Journal Article Research Support, Non-U.S. Gov't Biofuels Esters Fatty Acids Linoleic Acids Linolenic Acids Lipids Oils Palmitic Acids
Beschreibung
Zusammenfassung:In this work, a mixture of chloroform and methanol (1:1, v/v) was applied to oil extraction from Chlorella sp. at 30, 40, 50 and 60 degrees C for 150 min extraction times. Kinetic studies revealed that the values of n and the rate constants were found to depend strongly on temperature. The activation energy was Ea = 38.893 kJ/mol, and the activation thermodynamic parameters at 60 degrees C were ΔS≠ = -180.190 J/mol , ΔH≠ = 36.124k J/mol and ΔG≠ = 96.128k J/mol. Both ΔH and ΔS yielded positive values, whereas ΔG was negative at 60 degrees C, indicating that this process is endothermic, irreversible and spontaneous. The acidic transesterification process was also investigated by gas chromatographic analysis of the microalgae fatty acid methyl esters (biodiesel) at different temperatures and reaction times. The fatty acid profile indicated that the main components were palmitic, linoleic and linolenic acids. The concentration of linolenic acid increased and oleic acid decreased as the temperature increased. Two-hour transesterification is the best reaction time for biodiesel production because it produces the highest percentage of unsaturated fatty acids (74%). These results indicate the potential of Chlorella sp. to produce biodiesel of good quality
Beschreibung:Date Completed 10.04.2014
Date Revised 20.03.2014
published: Print
Citation Status MEDLINE
ISSN:0959-3330